Notes on Screw Gauges -NPL

[Michael GilliganParticipant @michaelgilligan61133]

Whilst pondering the discussion here: **LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=183696&p=1

I found this 133 page ‘booklet’ yesterday: **LINK**

https://www.npl.co.uk/dimensional/screw-gauge-booklet

… and would rate it ‘astonishing’

In a world increasingly full of that’ll do approximations [the camera/tripod specification springs to mind], it is interesting to look at the pages numbered 79 and 80

[quote]

Whitworth Thread Form
The depths of thread calculated from the data in Fig. 42 are rounded to the nearest 0.0001 in., and are given, together with the corresponding values for s, r and H in Table 10.

[/quote]

The whole booklet is full of little surprises !

Not easy reading, but a useful reference by the Masters of the Art.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

[Paul LousickParticipant @paullousick59116]

Some good reading about gauges for screw threads.

One of my previous jobs was working for Borg Warner (American automotive supplier) in Australia, designing gauges in in one of their gearbox manufacturing plants. Gauges were use on their production lines and in their metrology labs. Learnt a lot about tolerances and the accumulation of errors when dimensioning a drawing. Gauges for measuring shafts, etc to ± 1/1000" tolerance had to be made ± 2/10000".

[Author]

Posts